The stud bay where your new shower will live is empty right now. Bare wood, subfloor, maybe a drain pipe stub sticking up through the floor. You are not renovating an existing shower. You are building one from nothing, and the difference between the two is about forty extra hours of work and roughly two hundred decisions you did not know you had to make.
Installing and tiling a shower from scratch means building the pan that holds the water, the curb that keeps the water inside, the walls that carry the tile, and the waterproof envelope that protects everything behind them. The tile goes on last. Everything that matters goes underneath it.
The Three Decisions You Make Before You Touch a Single Board
The shape of the shower determines every material choice that follows. An alcove shower with three framed walls and one open side is the most common DIY project because two of the walls already exist. A corner shower with two framed walls and a glass enclosure on the diagonal costs more in glass but wastes less floor space. A walk-in shower with no curb and a linear drain looks sleek but demands a recessed subfloor or a raised bathroom floor to get the slope right, and it is not a first-timer project unless you are already tearing out the entire bathroom floor.
Once you know the shape, decide between a site-built mortar bed and a prefabricated foam shower pan. A mortar bed costs $40 to $60 in materials and fits any drain location and any shower footprint. A prefab pan costs $200 to $500 and locks you into its exact dimensions and drain center point, but it arrives with the correct slope already molded in. If your drain is already centered and your shower is a standard size (36×36, 48×36, 60×32), the prefab pan removes the single most technically demanding step in the entire project.
The curb decision follows from the pan decision. A traditional curb built from stacked 2×4 lumber wrapped in backer board and waterproofing costs almost nothing and works with any pan type. A foam curb bonded to a prefab pan is faster. Skipping the curb entirely requires recessing the shower floor into the joist bay, which is structural work that needs an engineer’s sign-off in most jurisdictions. Nearly every first-time installer should build a curb.
Building the Shower Pan — Where Water Goes Where You Tell It To
A shower pan is a sloped mortar bed that directs every drop of water toward the drain. The slope must be a minimum of 1/4 inch per foot, measured from the farthest corner of the shower to the drain. That means a 48×36 shower with a center drain needs the perimeter to be roughly 3/4 inch higher than the drain. Less slope than that and water sits on the floor. More slope than 1/2 inch per foot and you feel like you are standing on a hill.
Mix dry-pack mortar at roughly 4 parts sand to 1 part Portland cement. Add just enough water that the mix holds its shape when squeezed in your fist but crumbles when you poke it. It should feel like damp beach sand, not wet concrete. Too much water and the mortar shrinks as it cures, cracking the pan. Pack it in lifts, compact it firmly with a wooden float, and screed it with a straightedge riding on the perimeter screed strips you set first.
For a traditional two-stage mortar bed, the first layer (the pre-slope) goes directly on the subfloor, sloping toward the drain. A PVC or CPE liner goes on top, running up the walls at least 3 inches above the finished curb height and clamped to the drain body. The second layer (the setting bed) goes on top of the liner at a uniform 1-1/4 to 1-1/2 inch thickness, following the same slope as the pre-slope. This top layer is what you tile onto. The liner between the two layers is the actual waterproof barrier for the floor.
| Layer | Material | Thickness | Purpose |
| Pre-slope | Dry-pack mortar (4:1) | 3/4″ at drain, rising | Creates slope under liner |
| PVC/CPE liner | 40-mil minimum | N/A | Waterproof barrier |
| Setting bed | Dry-pack mortar (4:1) | 1-1/4″ to 1-1/2″ uniform | Tile substrate |
A prefab foam pan skips all of this. You thinset it to the subfloor, connect the drain, and the slope is already built in. The trade-off is that the subfloor underneath must be perfectly flat and level. A foam pan on a floor that dips 1/8 inch will rock, and rocking pans crack tile.
The Curb, the Drain, and the Flood Test
Build the curb from three stacked 2×4s screwed into the floor and wall studs. Wrap it in backer board, then waterproof it as part of the continuous membrane that ties into the wall waterproofing and the pan liner. The finished curb must stand at least 2 inches above the finished drain height per plumbing code. That height difference, combined with the pan slope, keeps a small lake of backed-up water from spilling over the curb while the drain catches up.
The drain assembly for a traditional mortar bed is a three-part clamping drain. The bottom flange sits on the subfloor and connects to the waste pipe. The liner gets clamped between the bottom and middle flanges. The top adjustable collar threads into the middle flange and sets the final drain height to match your floor tile thickness. The weep holes in the middle flange are the detail that makes the whole system work: any water that seeps through the grout and setting bed hits the liner, flows down the slope, and exits through these weep holes into the drain pipe. If you block the weep holes with mortar or debris during construction, water has nowhere to go and eventually saturates the setting bed.
Before a single tile touches the floor, fill the pan with water up to the bottom of the curb and mark the water level with a piece of tape. Wait 24 hours. If the water drops at all, find the leak before you cover everything with tile. A flood test that passes is the only proof you will ever have that the pan does not leak. The tile on top of it will never tell you.
A plumber I worked with once told me he has never seen a failed shower pan that the homeowner knew about before the tile went up. The failures announce themselves six months later as a water stain on the ceiling below.
Walls, Backer Board, and the Waterproof Envelope
Hang cement backer board on the walls with the rough side facing out. Screw it every 6 to 8 inches along every stud, keeping fasteners 1/2 inch back from the edges to prevent crumbling. Tape every seam and every inside corner with alkali-resistant mesh tape embedded in thinset. The backer board is not waterproof. It is dimensionally stable when wet, which is different.
The waterproofing layer goes on after the board is up and the seams are taped. Roll or trowel a liquid membrane (RedGard, Hydro Ban, Aquadefense) across every surface that will see tile, including the curb top and inside faces. Apply it at the manufacturer’s specified thickness using a wet-film gauge. Two coats minimum, with the second coat applied perpendicular to the first. The membrane must extend at least to the height of the shower head. Pay obsessive attention to the inside corners where walls meet the pan. These corners move slightly as the house settles, and they are where most shower leaks originate.
Tiling the Walls and the Floor
Tile the walls before the floor, working from a ledger board screwed into the wall at the second row up. This keeps your wall rows level and gives you a clean bottom cut that follows the pan slope. On the floor, choose tiles no larger than 4 inches. Large-format tile cannot follow the compound slope of a shower pan without lippage. Mosaic sheets with a mesh backing conform to the slope and provide the grip that smooth large-format tile cannot.
Mix thinset to peanut butter consistency. Comb it with the notched side of the trowel at a consistent 45-degree angle, and press each tile in with a slight twist. Pull a tile off periodically during the first few rows. You need at least 95 percent coverage on the back of every tile in a wet area. A tile that sounds hollow when tapped a week later had air pockets behind it when it was set.
Cutting the floor tiles around the drain requires patience and a wet saw. Dry-fit every piece before you mix thinset. The four tiles surrounding the drain grate should be cut so the grate sits flush or slightly below the tile surface, never above it. A grate that sticks up creates a lip where water pools.
Grouting, Sealing, and When You Can Finally Use It
Wait a minimum of 24 hours after setting the last tile before grouting. The thinset underneath needs to cure, and rushing grout into joints that still have wet mortar behind them produces grout that cracks and falls out within months. For joints 1/8 inch and narrower, use unsanded grout. For wider joints and shower floors, use sanded grout. Epoxy grout costs more and sets faster, but it never needs sealing and it resists staining far better than cement-based grout.
Apply grout with a rubber float at a 45-degree angle, packing joints fully before striking off the excess. Wipe the tile faces with a damp sponge after the grout firms up (about 15 to 30 minutes). Buff the remaining haze with a dry microfiber cloth after another hour. Seal cement-based grout with a penetrating sealer 48 to 72 hours after grouting.
The full cure timeline: thinset reaches final strength after about 7 days. Grout and sealer need 48 to 72 hours before the shower sees water. Silicone caulk in the corners and at the wall-to-pan joint needs 24 hours. The soonest you should use the shower after finishing is 3 days. A full week is better. The shower you built will last decades. Waiting a week to use it is the smallest part of the investment.
FAQ — Installing and Tiling a Shower
How long after tiling can I actually use the shower?
Three days at the absolute minimum: 24 hours for the thinset to set before grouting, 48 to 72 hours for the grout and sealer to cure, and 24 hours for the silicone caulk in the corners. Seven days is the manufacturer-recommended full cure for most thinsets. Using the shower earlier risks pulling moisture into the grout joints before the sealer bonds, which permanently reduces its effectiveness.
Can I build a shower without a curb?
Yes, but it is not a beginner project. A curbless shower requires the shower floor to be recessed below the bathroom floor level, which means either cutting into the floor joists (structural work requiring an engineer) or raising the entire bathroom floor to create a slope within the shower footprint. A linear drain at the back wall makes curbless designs easier because the floor only slopes in one direction instead of four.
What is the hardest part of installing a shower from scratch?
The mortar bed. Mixing dry-pack to the right moisture level, packing it without overworking it, and screeding a consistent slope toward a drain takes practice that most people get exactly once before they have to live with the result. The second hardest part is the flood test, because waiting 24 hours to see if water moved by an eighth of an inch is genuinely stressful. Everything after the pan — the backer board, the waterproofing, the tile — is methodical and recoverable. The pan either works or it does not, and fixing it means tearing out everything on top of it.
Last modified: June 12, 2026
